This is linked with Match Play within the programming module - not tournaments module.
Step 1: Set up the round-robin events in the Serve Tennis admin pages
Creating Match Play Adult and Junior Match Play in Programming
Step 2: Download the App to manage your Round Robin
You can do this from the app stores (iOS and Android) and search for USTA programming
Apple / iOS products or Google Play App Store
Step 3: Once downloaded, login to your app using your USTA username and password. Search for the start date of the event you have created.
You will then enter into the schedule view where you can view all of the upcoming sessions you set up in the Match Play module by clicking through the dates on your schedule.
See: Match Play App - Managing a Match Play Program